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Volume 53, Issue 9
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Research Paper
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Song-nan HUANG, Yasuro FUSE, Etsu YAMADA2004 Volume 53 Issue 9 Pages 875-881
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe measurement of hydrogen peroxide and organic peroxides in the atmosphere and rainwater was developed, and the behavior of these peroxides affecting forests was investigated. The seasonal variation of atmospheric H2O2 in Kyoto (0.18∼6.96 ppbv) showed a summer maximum and a winter minimum. Methylhydroperoxide (MHP) was mainly detected in the atmosphere with a level of 0.07∼0.29 ppbv during June and September. Organic peroxides in the atmosphere increased above ca.25°C, and correlated with the O3 concentration and relative humidity, while atmospheric H2O2 was inversely correlated with the relative humidity. They were not related to solar radiation and UV radiation. The H2O2 concentration in rainwater was higher than 50 μM in the summer. Hydroxymethylhydroperoxide (HMHP) and MHP as organic peroxides were detected in rainwater with low concentrations of less than 2 μM during June and August.
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Takashi YAMADA, Michiaki SUMITA, Yoshiaki NAKANISHI, Takaharu HONJO2004 Volume 53 Issue 9 Pages 883-889
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSIn this study, we tried to solve heavy-metal pollution and its state in rivers from both chemical and biological viewpoints. The sediment (sediment on the river bed and attached substances, etc.) was taken in rivers at the feet of old copper mines, Ishikawa prefecture. Its wet ashing and sequential extraction were performed. The total copper content and the copper contents of all fractions containing the types of associations between copper and the sediment were determined. The diatom taxa, growing in attached substances on psephite, were also identified. As a result, the correlation between the ratio of the exchangeable fraction (e.g. ion-exchangeable chemical species and carbonate) to the total contents of copper and the relative abundance (as the ratio of the number of each taxon to the total number of diatom) of Achnanthes minutissima, which is specified as an indicator diatom of heavy-metal pollution, was observed. The exchangeable fraction contained toxic species of copper. It seems that they have an effect on biota containg diaton in rivers.
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Hitomi NAKAJIMA, Kouichirou OKADA, Hiroyuki FUJIMURA, Takemitsu ARAKAK ...2004 Volume 53 Issue 9 Pages 891-897
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe photochemical formation of peroxides (hydrogen peroxide and organic peroxides) was studied in seawater collected along the coast of Okinawa Island, using a solar simulator. Our study showed that hydrogen peroxide (HOOH) was photochemically formed, but organic peroxides were not. The mean value of the HOOH photo-formation rates was 1.38 ± 0.80 nM min−1. We observed two types of HOOH formation kinetics, i.e. one with a constant formation rate and the other with a decreasing formation rate. Strong correlations were observed between the HOOH formation rate, the dissolved iron concentrations (R = 0.75) and the absorbance of seawater samples at 300 nm (R = 0.83). The dissolved organic carbon (DOC) concentrations did not show a strong correlation with the HOOH formation rate (R = 0.30). It is suspected that the compositions of dissolved organic compounds collected from different sites may differ, and that the photochemical formation of HOOH is affected by the compositions of dissolved organic compounds. The salinity showed a strong negative correlation with the HOOH formation rate (R = −0.76), suggesting that major HOOH-forming chromophores originate from land.
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Naoko TAKEUCHI, Shinya TAKESHIGE, Wataru NAGATSUKA, Heisaburo SHINDO, ...2004 Volume 53 Issue 9 Pages 899-904
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSSeveral aqueous-aqueous polymer two-phase systems were searched for the countercurrent chromatographic (CCC) separation of proteins. The selective separation of ovomucin from egg white was performed by CCC using a two-phase system composed of 15%polyethylene glycol (PEG) 1540-dextran T10-100 mM potassium phosphate at pH 7.0. Ovalbumin, conalbumin and lysozyme having small partition coefficients were eluted from the column with dextran-rich lower phase as a mobile phase. On the other hand, ovomucin with the large partition coefficient showed a high affinity to the upper stationary phase. After elution of the ovalbumin, conalbumin and lysozyme, the ovomucin was collected from the column by pushing out with air. After purification, PEG 1540 and dextran T10 were easily eliminated from the CCC fractions by ultrafiltration for a short time. The proteins in the CCC purified fractions were detected by SDS polyacrylamide gel electrophoresis.
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Fumihiro KODERA, Minoru UMEDA, Akifumi YAMADA2004 Volume 53 Issue 9 Pages 905-910
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSIn this paper, the development of a new electroanalytical method based on an anodic reaction for the hypochlorite ion is described. The determination was carried out by linear sweep-voltammetry at a Pt electrode. The peak current of observed oxidation wave was proportional to the amount of hypochlorite ion. The influences of various physical and chemical factors (repeatability, supporting electrolyte, pH, sweep rate, temperature, metal ion, and dissolved oxygen) were investigated. A fairly good correlation (R2 = 0.987) between this method and iodometric titration was achieved for standard samples (n = 5). This method seemed to be very useful to analyze the hypochlorite ion.
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Kazuyuki ISHII, Yuka TANAKA, Kyoko HATA, Masaharu GOTO, Kazunori SAITO ...2004 Volume 53 Issue 9 Pages 911-917
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe optimum experimental conditions for J coil planet centrifuge high-speed countercurrent chromatography (HSCCC) with aqueous biphasic systems consisting of polyethylene glycol (PEG) and sodium sulfate were investigated using some inorganic anions as model compounds. The PEG-rich upper phase was used as the stationary phase and the salt-rich lower phase was used as the mobile phase. In order to eliminate fluctuations of the base line of chromatograms owing to emulsification caused by excessive mixing of the two phases, water was mixed with the eluate from the column prior to UV detection. The resolution of iodate ion and iodide ion increased with an increase in the revolution speed of the Teflon tube column holder although the volume of the stationary phase retained in the column decreased. This was due to an improvement of the separation efficiency, shown as an increase in theoretical number of sample compounds. The increase in the flow rate of the mobile phase caused a decrease in the stationary phase volume. However, the resolution did not depend on the flow rate in the range studied. This may be interpreted in terms of relatively high distribution ratios of the inorganic anions used in this study. Separation of some inorganic anions and that of chromium(III) ion and chromate(VI) ion were easily accomplished by HSCCC with PEG#1000-16.7%(w/w) Na2SO4 aqueous biphasic system.
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Akinori GOTO, Mitsuko OSHIMA, Toshio TAKAYANAGI, Shoji MOTOMIZU2004 Volume 53 Issue 9 Pages 919-923
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSFor the spectrophotometric determination of anionic surfactants in aqueous media, cationic dyes with a 2,2'-thiacyanine skeleton were newly synthesized. Carbon numbers of 4 and 6 in the n-dialkyl chain combined at the N position of 2,2'-thiacyanine are new compounds. Fundamental information, such as the pKa values, was obtained. These two compounds and purchased diethyl- and dipropyl-2,2'-thiacyanine were examined for the spectrophotometric determination of an anionic surfactant, DBS. Of these, 3,3'-dihexyl-2,2'-thiacyanine (DHT) showed the best sensitivity. The calibration graph for DBS with DHT was linear up to 1×10−5 M, and the detection limit was 4×10−7 M. By a hydrophobic interaction, even a cationic surfactant, Zephiramine, and a nonionic surfactant, Triton X-100, could react with DHT. The ion-association constants for these surfactants with DHT were obtained.
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Kuniko NAKAMURA, Yoshihito OHBA, Naoya KISHIKAWA, Naotaka KURODA2004 Volume 53 Issue 9 Pages 925-930
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA sequential injection analysis (SIA) with chemiluminescence detection for measuring the antioxidative activity against hypochlorite ion was developed. The antioxidative activity was expressed as the percentage inhibition of luminol chemiluminescence due to the scavenging of hypochlorite ion by an antioxidant. Using a 50 mM borate buffer (pH 9.5) as a carrier, the SIA system was optimized with respect to the reagent concentrations, volume and flow rates. The SIA system could measure 3 samples within 4 min. The relative standard deviations of the antioxidative activity for 2 nM ascorbic acid were 2.5% (within-day, n = 3) and 3.7% (between-day, n = 3). Several antioxidants, such as ascorbic acid, α-tocopherol and Trolox, were successfully measured by the SIA system, and the relationships between their antioxidative activity and the logarithm of concentrations of antioxidants were linear (r = 0.983−0.999). The proposed SIA system was rapid, sensitive and reproducible with minimum consumption of the reagents, and was thus useful for the rapid screening of antioxidants possessing antioxidative activity against hypochlorite ion.
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Makiko KAJIWARA, Masashi NISHIDA, Isao YOSHIDA2004 Volume 53 Issue 9 Pages 931-936
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe complex formation reaction of p-nitrocalix[6]arene, CALX-N6, with a uranyl ion, UO22+, was studied by the pH titration method in a 20% acetone aqueous solution at 20°C and μ = 0.01. From the absorption data of CALX-N6, the acid dissociation constants were determined to be as follows : pKa1 = 2.72, pKa2 = 5.71 and pKa3 = 11.59. These results indicate that CALX-N6 is a relatively strong tri-protonic acid, H3L, which releases 3 mol of protons from 1 mol of CALX-N6, having 6 mol of hydroxyl groups, in a weakly acidic to an alkaline solution. CALX-N6 formed four 1 : 1 complex species with UO22+. From the pH titration data for the CALX-N6 - UO22+ mixture solution, the log overall stability constants, log βmlh, of these 1 : 1 complexes were determined to be as follows : 17.3 for 111 (UO2LH), 12.1 for 110 (UO2L−), 7.27 for 11-1 (UO2LH−12−) and 1.08 for 11-2 (UO2LH−23−) where βmlh = [(UO2)mLl Hh]/([UO2]m[L]l[H]h). These acid-dissociation and complex-formation behaviors of CALX-N6 to UO22+ are similar to the case of water-soluble calix[6]arene-p-sulfonate, CALX-S6, which is a super uranophile.
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Atsushi SUZUKI, Hideyuki UZU, Shinichi MASUOKA, Xiong LI, Lee Wah LIM, ...2004 Volume 53 Issue 9 Pages 937-941
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSMonolithic silica capillary columns have an advantage over conventional densely packed columns in terms of their higher permeability. The inlet pressure and the column length have been optimized. By applying moderate inlet pressures, benzene and five kinds of alkylbenzenes could be separated on a monolithic ODS-bonded silica capillary column within one minute.
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Sachie UCHIDA, Yuichiro KOMATSU, Hitomi SATOH, Setsuko YAJIMA, Keiichi ...2004 Volume 53 Issue 9 Pages 943-952
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSWe desinged seven neutral carriers for hydrophilic anion sensors : four compounds containing one thiourea group and dendritic benzyl ether derivatives, two compounds containing three or four thiourea groups, and a cyclic compound containing three thiourea groups. The association constants with dihydrogen phosphate ion for these thiourea derivatives were determined in organic solvents. The compounds exhibited high association constants with dihydrogen phosphate ion. When these compounds were used as neutral carriers of ion-selective electrodes (ISEs) for phosphate ion, the slopes of the EMF responses were very small in all cases. The ISEs showed better EMF responses for sulfate ion than for phosphate ion. Especially in the case that dendritic and cyclic derivatives containing three thiourea groups were used as neutral carriers, the ISEs exhibited excellent EMF responses for sulfate ion and anion selectivities.
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Atsushi SHOJI, Akio YANAGIDA, Heisaburo SHINDO, Yoichi SHIBUSAWA2004 Volume 53 Issue 9 Pages 953-958
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSReversed-phase (RP) partition chromatographic separations of eleven kinds of catechins were performed by HPLC using on ODS monolith column and by high-speed countercurrent chromatography (HSCCC) with a two-phase solvent system composed of t-butylmethylether/acetonitrile/0.1% trifluoroacetic acid (2 : 2 : 3). Procyanidin C1 (PC1; trimeric epicatechin) was strongly retained to the ODS column of RP-HPLC in spite of its smallest value of the octanol/water partition coefficient (log P) among the catechins tested. On the other hand, the retention time of each catechin upon RP-HSCCC separation was decreased with decreasing value of log P. Thus the most hydrophilic oligomer, such as PC1, was first eluted from the RP-HSCCC column.
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Sanae OTA, Takako YAMAGUCHI, Yoshikazu FUJITA2004 Volume 53 Issue 9 Pages 959-963
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA simple and sensitive spectrofluorometric method for the determination of pyrophosphoric acid, whose role is presumed to be a catalyst-like action, was established by utilizing condensation reaction between resorcinol and propionaldehyde. The calibration graph has good linearity over 0.007∼1.4 μg pyrophosphoric acid in 10 ml of the final solution, by measuring the fluorescence intensities of the sample and blank solutions at an emission wavelength of 457 nm with an excitation wavelength of 380 nm, respectively. The relative standard deviation for five replicate determinations of 0.14 μg of pyrophosphoric acid was 1.25%.
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Kentaroh FUJII, Shuhei TANIBUCHI, Sorin KIHARA2004 Volume 53 Issue 9 Pages 965-973
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA liquid membrane disk electrode, LMDE, and a liquid membrane ring-liquid membrane disk electrode, LMRE-LMDE, were developed by placing a solidified polyvinyl chloride thin membrane impregnated with 2-nitrophenyl octyl ether, NPOE-LM, on the surface of a glassy carbon, GC, disk or ring electrode. A couple of redox reagents and a supporting electrolyte were added into NPOE-LM. The voltammogram for the ion transfer at the interface between an aqueous solution, W, and NPOE-LM was recorded by setting the developed electrode in W and rotating at a rate, ω, between 0 and 4000 rpm. Though there exist two interfaces (W | NPOE-LM and NPOE-LM | GC interfaces) in the liquid membrane electrode system, the reaction at the objective W | NPOE-LM interface could be analyzed when the NPOE-LM | GC interface was depolarized by redox reactions of reagents of rather high concentrations added in NPOE-LM. The sensitivity of the ion-transfer current at the W | NPOE-LM interface, I, was enhanced to be more than 100 times better when LMDE was rotated at ω higher than 200 rpm. For examples, the limiting currents, Il, at LMDE observed for the transfer of tetraethylammonium ion, TEA+, from W to NPOE-LM and that for the transfer of K+ from W to NPOE-LM facilitated by dibenzo-18-crown-6 added in NPOE-LM were proportional to concentrations of TEA+ and K+, respectively, in W in the range between 10−7 and 2×10−6 mol dm−3 when ω was 1000 rpm. The standard deviation determined by 5 repeated measurements of Il for 10−6 mol dm−3 TEA+ was 3.2%. The reversibility of the ion transfer reaction could be evaluated based on the dependence of I on ω of LMDE, and the reaction product at LMDE could be identified at LMRE when rotating LMRE-LMDE system was adopted.
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Motonori NAKAO, Hiroaki MATSUMIYA, Masataka HIRAIDE2004 Volume 53 Issue 9 Pages 975-980
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSWater-in-oil (w/o) type emulsions were prepared by dissolving 0.10 mmol of chelating agent and 0.03 ml of non-ionic surfactant Span-80 in 2.0 ml of toluene and vigorously mixing with 0.5 ml of 1.0 moll−1 hydrochloric acid by ultrasonic irradiation. The resulting emulsions were gradually injected into 25 ml of sample solution and dispersed by stirring as numerous tiny globules. Traces of heavy metals (e.g. Co, Ni, and Cu) were diffused through the toluene layer into the small droplets of hydrochloric acid encapsulated in the emulsion. When thenoyltrifluoroacetone was employed as a chelating agent, the recovery of cobalt and nickel increased synergistically with the addition of 1,10-phenanthroline into the toluene layer, allowing the quantitative collection of these metals at pH 4. At this pH, the present emulsion enabled the simultaneous separation of cobalt, nickel, and copper from an aluminum matrix, and was successfully employed as a separation medium for the determination of these metals in high-purity aluminum and alumina by graphite-furnace atomic absorption spectrometry.
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Syunsuke KAWAGUCHI, Masaya KAMADA, Akifumi YAMADA, Minoru UMEDA2004 Volume 53 Issue 9 Pages 981-986
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe electrocatalyst layer of polymer electrolyte fuel cells(PEFCs) formed a three-phase interface by using a mixture of Pt/C and a proton-conductive polymer. In the case where Nafion was used as a proton-conductive polymer, some extent of platinum particles of Pt/C were covered by a insulation property cluster of Nafion; therefor, an efficient formation of the three-phase interface was not achieved. In the present study, polyelectrolyte complex(PEC) was used with Pt/C instead of Nafion. PEC, which has a small cluster size, could be expected not to cover the Pt particle. An electrode catalyst layer consisting of the Pt/C and a PEC was prepared on an Au flag electrode. The platinum utilization efficiency was measured by cyclic voltammetry. As a result, it was found that the Pt surface area of the Pt/C-PEC was 1.5-times larger than that of Pt/C-Nafion.
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Tsuneaki MAEDA, Miki TAKIZAWA, Tatsuro NAKAGAMA, Katsumi UCHIYAMA, Tos ...2004 Volume 53 Issue 9 Pages 987-991
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSSpectrophotometric measurement is a popular and easy technique for the determination of pollutants. In most cases, cumbersome enrichment procedures, using several toxic and environmentally harmful organic solvents, are required in the pretreatment step of the measurement. Recently, solid-phase micro extraction (SPME) using a liquid phase for gas chromatography (GC) has been used for the sample preparation of environmental pollutants in GC and liquid chromatography. In this study, a solvent-less extractive enrichment technique using a GC liquid phase was developed. The membrane of the liquid phase was prepared on a quartz plate, and the prepared plate was dipped into a chromophore aqueous solution for a given time. The plate was then dipped in aluminum aqueous solution. It was expected that aluminum ion could be extracted into the polymer liquid membrane and complexed with the chromophore. When a plate with a cationic silicone liquid membrane of 30 micro meters in thickness containing Pyrocatechol Violet (PV) was dipped in ca. 25 ml of an aluminum aqueous solution, the absorbance of the spot at the wavelength of the maximum absorbance of the aluminum gradually increased, and that of the PV gradually decreased. The detection limit of aluminum was 0.23 μg (3σ). This method was applied for ppb-level alminum determination using PV as a chromophore and a polymer liquid phase.
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Taketoshi NAGAYASU, Hideo HAYASHI, Masataka HIRAIDE2004 Volume 53 Issue 9 Pages 993-996
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA combined method of laser ablation (LA) and ICP-MS has gained much attention as a direct analytical method for solid samples. The determination of some elements, however, is seriously disturbed by isobaric interferences, mainly caused by argon and ambient air constituents. The use of low-pressure helium-ICP is a promising solution of the problem. A 1 : 1 mixture of alumina powder and glycerol was deaerated and irradiated with a pulsed laser beam (150 mJ) for 10 s. The sample aerosol was transported to the ICP with a stream of helium. Indium was used as an internal standard for correcting the ablated sample amount. Calibration curves were prepared from glycerol containing high-purity alumina, trace metals and indium. The detection limits for Cr, Mn, Fe, Co, Ni, and Cu approached the fractional ppm levels. The proposed method was successfully applied to the analysis of different alumina samples (99∼99.995% purity).
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Note
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Keiichiro YAMAMOTO, Takayuki NAKAI, Yoshiko MURAKAMI, Yoshiaki SASAKI, ...2004 Volume 53 Issue 9 Pages 997-1001
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe separation and recovery of chromium(VI) by using a cationic surfactant were investigated. Chromium(VI) reacted with cetylpyridinium chloride (CPC) to form a (HCr2O7−)(CP+) ion-pair under an acidic condition. This ion-pair was sparingly soluble in water, and was separated as a precipitate with CPC from aqueous solution by centrifugation. In order to desorb the chromium(VI) from CP+, the reduction of chromium(VI) to chromium(III) having positive charge was performed by using sodium sulfite in the presence of sulfuric acid. Finally, chromium was then recovered as Cr(OH)3 under a basic condition. Optimization for the quantitative recovery of chromium(VI) was carried out. This method was applied to the recovery of chromium(VI) in chrome plating including Cr(III) + (VI), Fe, Zn, Cu, Al, Mn and Sb.
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Ryuji TAKEDA, Yoshimasa IKUMA, Sadayoshi MATSUMOTO, Sadao KOMEMUSHI, A ...2004 Volume 53 Issue 9 Pages 1003-1008
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSPAHs are the general term of the compounds, having two or more benzene rings. These are discharged from diesel motor gas, tanker accidents, oil emissions by cars, and so on. They float in the atmosphere, and it is considered that they are absorbed in soil as a result of rain. Generally, compounds that have two or three benzene rings show only toxicity, whereas these having four or more benzene rings show toxicity, carcinogenicity and mutagenicity. Especially, benzo(a)pyrene was shown to be an agency of an endocrine disrupter. We investigated the action of 16 PAHs specified by the U.S. EPA in soil around Nara city. Soil was collected from different locations involving traffic and vegetation. Soil from three locations around our university were collected every month for investigating seasonal movement. PAHs were extracted from soil by soxhlet extraction with dichloromethane. They were then analyzed quantitatively by HPLC/UV. We classed PAHs by the number of rings, and examined the concentration and seasonal movements. All content of 16 PAHs in soils increased in proportion to traffic volume. At the same locations of traffic volume, the gravitation at a location with a plant with all 16 PAHs in soils was, furthermore, found to have a low concentration. There were different seasonal movements of the 2,3-ring and 4, 5, 6-ring PAHs. 4, 5, 6-ring PAHs have strong correlations each others(r > 0.79), but there was no correlation between 2, 3-ring and 4, 5, 6-ring PAHs. As a result, the traffic volumes are exposition sources of 4, 5, 6-ring PAHs in soils.
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Takuroh NOGUCHI, Hiroki ARASAKI, Tamotsu OOMORI, Jitsuya TAKADA2004 Volume 53 Issue 9 Pages 1009-1013
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSAn age determination and the chemical composition of hydrothermal barite, collected from an Okinawa Trough hydrothermal field, were studied. Initially contaminated 210Pb in sulfide and other minerals were leached by a chemical treatment. After the treatment, the radioactivity and chemical composition were determined by gamma spectrometry and neutron activation analysis, respectively. The following results were obtained: 1. An accurate and reproducible age was obtained by a chemical treatment of barite samples. 2. A matrix effect of barite samples on gamma-ray measurement was significantly observed, and was calibrated with mixed NaCl-BaSO4 references. 3. The precipitation age, calculated by the 210Pb/226Ra method after correction was concordant with the 228Th/228Ra and 228Ra/226Ra methods. 4. The Sr/Ba weight ratios were in the range of 0.007∼0.053, which seems to have positive relationship with the temperature of the hydrothermal vent fluid. 5. A chronological study of barite in sample No. 974R1 showed that Sr/Ba weight ratio seems to be high in older samples, and tends to decrease in young samples, which would suggest a possible alteration of the hydrothermal activity in this field.
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Yuki IWASAKI, Naoki KANO, Kazuhiro OMORI, Hiroshi IMAIZUMI, Toshio ISH ...2004 Volume 53 Issue 9 Pages 1015-1019
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA simple and an efficient preconcentration method for the separate determination of each species of chromium {i.e., Cr(III) and Cr(VI)} in environmental water samples has been investigated, followed by inductively coupled plasma-atomic emission spectrometry (ICP-AES). This method is based on the following ion-exchange method. Cr(III) was adsorbed on cation-exchange resin, and Cr(VI) on anion-exchange resin. The retained Cr(III) and Cr(VI) were quantitatively eluted with 2 mol dm−3 hydrochloric acid (HCl) and 2 mol dm−3 potassium chloride (KCl), respectively. The preconcentration factor was 100 for Cr(III) and 300 for Cr(VI) in this work, and the detection limits were 0.03 μg dm−3 in Cr(III) and 0.01 μg dm−3 in Cr(VI). The method has been applied to environmental water samples from Niigata Prefecture. The recoveries of Cr(III) and Cr(VI) in environmental water samples were all 94∼98%, and the effect of interference from the coexistence ion was not detected. Therefore, the above-mentioned method is applicable to environmental water samples.
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Kazuyoshi MINAMISAWA, Takashi YOKOYAMA, Michio ZENKI2004 Volume 53 Issue 9 Pages 1021-1024
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSThe spectrophotometric determination of Fe(II) with 1,10-phenanthroline (phen) was carried out by a cyclic flow-injection analysis. Tandem glass columns (4 mm i.d., 8 cm long, each) packed with polyurethane foam (PUF, weight; 0.16 g×2) for the removal of Fe(II)-(phen)3 complex were incorporated in the system, allowing a repetitive determination of Fe(II). A solution of 2.0×10−3 M phen and 5.0×10−4 M sodium dodecyl sulfate (SDS) in a 0.1 M acetate buffer (pH 4.7) in a single reservoir (50 ml) was continuously circulated at a constant flow rate of 1.5 ml min−1. Into the stream, an aliquot (5 μl) of a sample containing Fe(II) was injected by means of a 6-way valve. The formed complex was monitored spectophotometrically at 510 nm. The stream was passed through glass columns, which were introduced after the flow-through cell, and then returned to the reservoir. The colored Fe(II)-(phen)3-SDS ion associates were adsorbed onto PUF, which allowed a baseline constant, and made it possible to adopt a cyclic FIA. This method allowed as many as 100 repetitive determinations of 6 ppm Fe(II) solutions with the same 50 ml of the circulating solution.
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Chidsuru SATOU, Mariko KOBAYASHI, Ai TAKEDA, Taeko ITO, Kenji SHIMADA, ...2004 Volume 53 Issue 9 Pages 1025-1029
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA convenient analytical method using high-temperature gas chromatography for the determination of mono- and diacylglycerols, lipase-catalyzed cleavage products of triacylglycerol (TG), has been developed. In this study, analytical conditions were examined using triolein (TO), diolein (DO) and monoolein (MO) as standard materials. As a result, a trimethylsilyl(TMS) derivatization with N,O -bis(trimethylsilyl)acetamide and a well-programmed column temperature using a low polar capillary column permitted the regiospecific analysis of 1-MO, 2-MO, 1,2-DO and 1,3-DO. Solid-phase extraction using an aminopropyl silica cartridge was effective for the sequential treatment of lipase-catalyzed cleavage products of TO. A quantitative analysis became feasible by the use of tricaprin as an internal standard. It was suggested that the present method was useful for the analysis of a different manner of cleavage due to the different kinds of TGs and lipases.
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Sosuke MATSUEDA, Eiko NAKAMURA2004 Volume 53 Issue 9 Pages 1031-1033
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSWe reported on a spectrophotometric method for the determination of polyoxyethylene nonionic surfactants(NS) using a polytetrafluoroethylene(PTFE) membrane filter in a previous paper. The method is based on the collection of NS on the filter, and the formation of an NS- iron(III)-thiocyanate complex. Although it is a simple and rapid method, it is not good regarding the precision of repeated blank tests, because of the instability of a mixed solution of potassium thiocyanate and iron(III) chloride. In the present work, the concentration of the potassium thiocyanate and iron(III) chloride solution was studied in detail to improve the precision of repeated blank tests. The improved procedure was as follows. After a 100 ml sample solution(0∼120 μg heptaoxyethylenedodecylether) was filtered through a PTFE filter (pore size : 0.1 μm, Φ : 25 mm), 2 ml of a potassium thiocyanate solution(6 M) and 2 ml of an iron(III) chloride solution(8 mM) were added on the filter, respectively. NS associated with iron(III)-thiocyanate was eluted with 5 ml of methanol, and the absorbance of the solution was measured at 510 nm. The precision of repeated tests (n = 3) was ca. 2% on both the blank and the sample.
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Hiroshige UNO, Takashi SUZUKI, Yasumasa GOTO, Shinsuke ITOH, Takashi Y ...2004 Volume 53 Issue 9 Pages 1035-1038
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA few germanium(IV) complexes were prepared and examined for the anionophore. A nitrilotriphenolato complex ([Ge2(ntp)2O]) with three coordinating phenolates around Ge(IV) showed a sub-Nernstian response (40 mV/decade) to fluoride in the range of 10−3∼10−1 mol dm−3 as a carrier of ion-selective electrodes(ISEs). The dynamic range was extended to 10−4∼10−1 mol dm−3 in the presence of cationic additives. Spectroscopic studies on the reaction of this complex with anions in dimethyl sulfoxide demonstrated the reaction stoichiometry of Ge(IV) : A− = 1 : 1 and the thermodynamic stability order of F− > CH3COO− > H2PO4−. The reaction selectivity agreed with that of potentiometry with ISEs. A bis(catecholato) complex with four phenolates showed no response to anions, and a bis(aminophenolato) complex with two phenolates was not stable enough in the reaction with anions.
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Satoko YAMAKAWA, Koji OSHITA, Akhmad SABARUDIN, Mitsuko OSHIMA, Shoji ...2004 Volume 53 Issue 9 Pages 1039-1043
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSA chitosan-based resin possessing the iminodi(methylphosphonic acid) moiety (IDP-type chitosan resin) was synthesized by using cross-linked chitosan as a base material. The adsorption behavior of trace metal ions on the IDP-type chitosan resin was systematically investigated using a mini-column (1 ml of the resin) packed with the resin. The concentrations of metal ions in the effluents were measured by ICP-MS and ICP-AES. The resin could adsorb four metals, such as In(III), Sn(II), Th(IV), and U(VI), by almost 100% over a wide pH range (1∼7). Uranium(VI) and thorium could not be eluted with nitric acid and hydrochloric acid (1∼6 M); other metal ions were easily and readily eluted with 1 M nitric acid. The IDP-type chitosan resin synthesized in this work can be applied to the separation of U(VI) and Th(IV) from other metal ions.
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Analytical Report
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Shingo FUJITA, Eiko NAKAMURA2004 Volume 53 Issue 9 Pages 1045-1049
Published: 2004
Released on J-STAGE: December 24, 2004
JOURNAL FREE ACCESSInterference with chlorine on the formation of molybdenum blue was studied to determine the total phosphorus in sea water. When a sample containing chloride ion was digested with peroxodisulfate, chlorine was produced. The molybdenum blue formed in the absence of chlorine had absorption maxima at 880 and 710 nm, and the molar absorptivity at 710 nm was less than that at 880 nm. However, one of the absorption maxima of the molybdenum blue formed in the presence of chlorine shifted from 710 nm to 730 nm, and its molar absorptivity was larger than at 880 nm. The interference could be eliminated by boiling the digested sample and increasing the concentration of ascorbic acid in a mixed-reagent solution prepared by mixing acidic molybdate with ascorbic acid, but could not be eliminated by the addition of a sodium hydrogen sulfite solution.
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